Compaction, cutter, crusher unit



'D. M. WOOLDRIDGE Jan. 10, 1967 COMPACTION, CUTTER, CRUSHER UNIT 2 Sheets -Sheet 1 Filed Dec; 7, 1964 mm W INVENTOR BARREL M. WOOL DIE/06E Jan. 10, 1967' 0. M. WOOLDRIDGE 3,297,096

Y COMPACTION, CUTTER, CRUSHER UNIT Filed Dec. 7, 1964 v z Sheets-Sheet 2 j INVENTOR 57 DAR/85L M. WOOLDR/DGE BY n F I Era 5M H15 nrroma vs United States Patent 329K996 Patented Jan. 10, I967 ice 3,297,096 COMPACTION, CUTTER, QRUSHER UNIT Darrel M. Wooldridge, Oakland, Calif, assignor to American Tractor Equipment Corporation, a corpora: tion of California Filed Dec. 7, I964, Ser. No. 416,259 8 Claims. (Cl. 172- 164,)

This invention relates to an attachment for a road grader which is adapted to compact, cut and crush soil and rock and more particularly relates to a novel method of mounting such a device on a road grader and also a novel form of cutting disc for use in such a device.

It has heretofore been proposed to provide a cutting and compaction tool comprising a plurality of discs which are mounted as a unit on a road grader, wherein each of the discs comprises a series of scallops with hoe teeth interposed between each pair of scallops. In such prior art structures, the scallops extend outwardly beyond the hoes, so that on hard ground or asphalt surfaces, only the scallops contact with ground to break up the surface. This structure has been found to be not fully satisfactory for the reason that it is difficult to install such a structure, it tends to vibrate in use, and there is only a limited amount of down-pressure available for use. Thus the tool has usually been mounted upon the blade of the road grader. The blade is in turn mounted upon the circle which has many controllable movements, including positive down. pressure and angling. Sufficient down pressure is available to lift the front wheels of the grader off the ground. If too much down pressure is applied, the grader front wheels will lose traction and the grader cannot be steered except by the circle. As only one-third of the total grader weight is concentrated on the front wheels, there is a definite limit to the available down pressure. Further, the scallops on such a structure must be placed some dis tance apart because of the intervening hoes, so that al though one scallop will tend to start a crack, the following scallop is not close enough to form a continuation of the crack thus started; many passes are thus needed to break up a hard surface. Further, while the scallops on a given disc tend to propagate the cut or cracks in the direction of travel, because the scallops on the discs on each side of a given disc are immediately adjacent, these adjacent scallops interfere with and reduce the breaking-out movement of the material.

In accordance with the present invention, a novel form of disc is provided which has an alternate series of scallops and hoes, wherein the hoes extend well beyond the scallops, rather than being within the scallops. Further, the cutting blade or tooth of each hoe is at such an angle to the axis of rotation of the disc that each tooth falls exactly in or upon the out being made. This permits adjacent discs to be placed close together so that there is little separation between the initial cuts made by the hoes. Further, since the scallops do not extend outwardly as far as the hoes, there is no interference between the hoes and the scallops in the starting and propagation of cracks. Thus, the combination of the close spacing of adjacent hoes together with the fact that the scallops are held out of contact with hard ground, insures that there will be an initial breaking of a hard surface with a minimum number of passes. After a hard surface has been cut into strips, roughly corresponding to the distance between adjacent hoes on the same disc, the hoes start sinking into the ground, allowing the scallops to come into play and cut the strips made by the hoes into small pieces. Thus a hard surface, such as an old, pot-holed asphalt or oiled surface road, or a potential roadbed of hard clay with rocks therein, is first broken up and pulverized in a minimum number of passes to yield finely divided material. At this point, a blade can be used to level off the crushed material and to rough-shape the road, whereupon the device of the present invention is again used wherein it will tend to compact the finely divided material, leaving a road which is suitable for use for many purposes, or which is in proper condition for further improvement, such as the use of a smoothing roller followed by an oil treatment.

It is therefore an object of the present invention to provide a novel compaction cutter and crusher unit.

Another object of this invention is to provide such a compaction cutter and crusher unit having novel discs wherein a series of hoe teeth extend beyond an intervening series of scallop teeth.

Another object of this invention is to provide a compaction cutter and crusher unit which is so mounted on a road building machine whereby the amount of pressure applied by the compaction unit to the ground can be varied, and particularly so that pressure can be increased far beyond the weight of the compaction unit itself.

Another object of this invention is to provide a novel disc structure for such a unit which is easy to rebuild when the teeth are worn.

Still another object of this invention is to provide a mounting for such a unit which renders the unit easy to mount and dismount and which does not interfere with the steerability of the road grading machine.

Other objects will be apparent from the balance of the specification.

In the drawings forming part of this application:

FIGURE 1 is a perspective view of the compaction unit embodying the present invention, mounted on a road grader and showing the footprint on hard ground.

FIGURE 2 is an enlarged side view of the device of the present invention, showing its method of mounting on a vehicle.

FIGURE 3 is a perspective view of one of the novel discs employed in conjunction with the present invention.

FIGURE 4 is a side view, partly in section, of the disc shown in FIGURE 3.

FIGURE 5 is an end view on the lines 55 of FIG- URE 4.

FIGURE 6 is a sectional view on the lines 6-6 of FIGURE 4.

FIGURE 7 is a sectional view on the lines 77 of FIGURE 4.

FIGURE 8 is a diagram of the footprint of the device of the present invention when traveling over relatively soft or previously worked ground.

Turning now to a description of the drawings by reference characters, there is shown in FIGURES 1 and 2 a road grader 9 having an attachment frame 11 mounted thereon at the rear of the grader, the frame carrying double-acting cylinder and piston structures 13. The earth working tool has side frame members 15 and 17, joined by a cross frame member 19. The side frame members have extension arms 21 thereon which are fastened to frame Ill by a pivot connection 22. The hydraulic cylinder and piston structures 13 are provided between frame 11 and arms 21. This enables the tool to be forced against the earth under much of the weight of the grader so that the breaking force of the hoe teeth is greatly increased. Since about two-thirds of the grader weight is carried on its rear wheels much of this can be applied effectively to the earth working tool so long as the grader maintains the required rear-wheel traction for its movement. If desired, but one hydraulic cylinder and piston need be employed.

A shaft 23 is rotatably mounted between the side frame members 15 and 17, the shaft supporting a cylindrical member 25. The cutter discs, generally designated 27, fit over the cylinder 25 as is shown in FIGURES 1' and 2.

The cutter discs themselves, as is shown in detail in FIGURES 3 through 7, are preferably made of cast steel and each has a pair of annular flanges 29 and 31, which form a fairly snug fit over the cylindrical member 25. On the periphery of the casting are the teeth which are in two forms, namely the hoe teeth, generally designated 33, and the scallop teeth, generally designated 35. The hoe teeth are spaced about 45 from each other, so that in a preferred embodiment of the invention there will be eight such teeth for each ring. The sides of the hoe teeth 37 form angles of about 45 with each other, and the top surface 39 of the teeth can either be straight or have a slightly raised center, as is shown. The tops of the teeth are skewed since each disc is offset with respect to adjacent discs, and it is desired that each row of hoes form a spiral.

The intervening scallops 35 are likewise spaced about 45 from each other, so that the center of each scallop is about 22 /2" from the center of the adjacent hoes. The outer surface of the scallop is sharpened, as at 41, and the surface forms roughly a half circle with its outer surface inset substantially from the circle formed by the points of the hoes. In addition, each of the scallops preferably has a secondary cutting surface 43, which extends on each side downwardly to the annular disc members 29 and 31, with sharpened edges generally parallel to the cutting edges of the hoes, i.e., normal to the path of travel.

Lugs 45 and 47 are provided on opposite sides of each disc as is shown in FIGURES 3, 4 and 5. Lugs 45 are provided in pairs spaced apart a distance to fit a lug 47 on the next adjacent disc. Lugs 47 are offset slightly from the center of the space between the dual lugs 45 so that when a plurality of discs is assembled, the discs'are prevented from turning relative to each other and are offset slightly from one another in spiral form as appears in FIGURE 1.

In addition to having the several discs arranged in spiral form, the cutting edge on each hoe is angled slightly with respect to the axis of rotation of the disc so that only one hoe cutting edge 39 engages the ground surface at a time. For example, in a successful form of the device the discs were arranged spirally so that the spiral had a lead of six feet for every 45 of rotation. Each cutting edge 39 was at a small acute angle to the axis of rotation so that only one edge at a time out into the surface. The angle of the cutting edge can be varied depending on the width of the unit and the amount of spiral present in the unit. In the unit described the angle was 7.

In the perspective view of FIGURE 1, the footprint of the device is shown, when traveling over a hard surface Which might be hard, dry clay or a previously oiled road. Here, only the hoe teeth have entered, since the surface is so hard that the device does not sink deeply enough into the ground for the scallops to enter. The hoes cut the hard surface with a series of sharp gashes 52. The spaces 53 between the gashes are very short. so that when one hoe starts to form a crack, the adjacent hoes form a continuation of the crack. Thus when a crack is once started, it is propagated completely across the width of the device. Because all of the adjoining teeth are landing in or on the continuation of this crack, there is no interference to the opening of the crack. Further, the road material itself can be moved forward or back without obstruction, since the scallop teeth at this point are well out of contact. In this manner, the initial breaking up of the hard surface is done entirely by the hoe teeth and the scallop teeth do not interfere with their operation.

When the surface is softer the scallops cut in as well as the hoes. This is shown in FIGURE 2 where the scallops cut the surface 59 to the depth of line 50.

As work continues, the pattern shown in the detailed view of FIGURE 8 develops. Here, the hoe teeth have not only entered the hard surface as at 55, but the cracking action has been such that the space 57 between adjacent teeth is also cracked, allowing the scallops to enter the surface. Thus, the condition is as is shown in FIG- URE 2, wherein the solid line 59 represents the surface of broken or soft ground. At this point, the scallops have entered as at 61 so that the long narrow strips into which the surface has been broken by the initial action of the hoes is now broken up into a series of small rectangular pieces. Further, the action of the secondary cutting members 43 is now apparent and results in further breaking as at 63. It is obvious that on separate passes, the tool will not pass over exactly the same path, resulting in further breaking up of the surface. After the surface is completely broken into relatively small pieces, further action of the device results in compaction of the small pieces, placing the surface in condition for use as a rough road or for further processing.

I claim:

1. A cutter disc for use on a road working device, comprising in combination a plurality of spaced hoe teeth having sharpened edges generally parallel with the axis of the disc and intervening scallop teeth having sharp cutting edges, placed at right angles to the axis of the disc, said hoe teeth extending outwardly substantially further than said scallop teeth, the sides of each hoe tooth forming an acute angle with each other and each of the scallop teeth being integral with the sloping sides of adjacent hoe teeth and having their cutting edges extending substantially from the sloping side of one adjacent hoe tooth to the other, and each of the scallop teeth having a secondary cutting edge extending at right angles to its first mentioned cutting edge.

2. The device of claim 1 wherein eight hoe teeth and eight scallop teeth are equally spaced around the disc.

3. The structure of claim 1, wherein the hoe teeth have a cutting angle of about 4. A road surface working unit mounted at the rear of a vehicle, comprising a frame member pivotally connected to said vehicle at the rear thereof and supporting a plurality of discs as defined in claim 1, and pressure means connected between said frame and said vehicle, whereby the unit can be pressed against the ground under the weight of the vehicle.

5. The structure of claim 1 wherein each sharpened edge on a hoe tooth is at a small acute angle to the axis of the disc.

6. The structure of claim 1 wherein each sharpened edge on a hoe tooth is at a small acute angle of about 7 to the axis of the disc.

7. A road working unit made up of a plurality of discs as defined in claim 1 and wherein the discs are assembled in spiral form.

8. A road working unit made up of a plurality of discs as defined in claim 5 and wherein the discs are assembled in spiral form.

References Cited by the Examiner UNITED STATES PATENTS 188,815 3/1877 Nichols l72540 322,567 7/1885 Stonesifer l72554 571,130 11/1896 Darling 17252 X 830,126 9/1906 Wilder 172-540 1,041,036 10/1912 Cunningham 172-548 2,169,917 8/1939 Keeler 172-464 X 3,173,493 3/1965 Renault l72548 X FOREIGN PATENTS 31,188 9/1884 Germany.

965 12/1852 Great Britain.

ABRAHAM G. STONE, Primary Examiner.

ANTONIO F. GUIDA, Examiner.

J. R. OAKS, Assistant Examiner. 

1. A CUTTER DISC FOR USE ON A ROAD WORKING DEVICE, COMPRISING IN COMBINATION A PLURALITY OF SPACED HOE TEETH HAVING SHARPENED EDGES GENERALLY PARALLEL WITH THE AXIS OF THE DISC AND INTERVENING SCALLOP TEETH HAVING SHARP CUTTING EDGES, PLACED AT RIGHT ANGLES TO THE AXIS OF THE DISC, SAID HOE TEETH EXTENDING OUTWARDLY SUBSTANTIALLY FURTHER THAN SAID SCALLOP TEETH, THE SIDES OF EACH HOE TOOTH FORMING AN ACUTE ANGLE WITH EACH OTHER AND EACH OF THE SCALLOP TEETH BEING INTEGRAL WITH THE SLOPING SIDES OF ADJACENT HOE TEETH AND HAVING THEIR CUTTING EDGES EXTENDING SUBSTANTIALLY FROM THE SLOPING SIDE OF ONE ADJACENT HOE TOOTH TO THE OTHER, AND EACH OF THE SCALLOP TEETH HAVING A SECONDARY CUTTING EDGE EXTENDING AT RIGHT ANGLES TO ITS FIRST MENTIONED CUTTING EDGE. 